Concerning AE data
With respect to AEs, deaths occurred in both groups (0.7% in those who took lecanemab and 0.8% in those who took the placebo). The researchers did not attribute any deaths to the drug. However, according to a report in the journal Science published Nov. 27, a 65-year-old woman who was taking the drug as part of a clinical trial “recently died from a massive brain hemorrhage that some researchers link to the drug.”
The woman, the second person “whose death was linked to lecanemab,” died after suffering a stroke. Researchers summarized a case report as saying that the drug “contributed to her brain hemorrhage after biweekly infusions of lecanemab inflamed and weakened the blood vessels.”
Eisai, which sponsored the new trial, told Science that “all the available safety information indicates that lecanemab therapy is not associated with an increased risk of death overall or from any specific cause.”
In a CTAD presentation, study coauthor Marwan Sabbagh, MD, Barrow Neurological Institute, Phoenix, said two hemorrhage-related deaths occurred in an open-label extension. One was in the context of a tissue plasminogen activator treatment for a stroke, which fits with the description of the case in the Science report. “Causality with lecanemab is a little difficult ...,” he said. “Patients on anticoagulation might need further consideration.”
In the CLARITY AD Trial, serious AEs occurred in 14% of the lecanemab group, leading to discontinuation 6.9% of the time, and in 11.3% of the placebo group, leading to discontinuation 2.9% of the time, the investigators reported.
They added that, in the lecanemab group, the most common AEs, defined as affecting more than 10% of participants, were infusion-related reactions (26.4% vs. 7.4% for placebo); amyloid-related imaging abnormalities with cerebral microhemorrhages, cerebral macrohemorrhages, or superficial siderosis (17.3% vs. 9%, respectively); amyloid-related imaging abnormalities with edema or effusions (12.6% vs. 1.7%); headache (11.1% vs. 8.1%); and falls (10.4% vs. 9.6%).
In addition, macrohemorrhage was reported in 0.6% of the lecanemab group and 0.1% of the placebo group.
Cautious optimism
In separate interviews, two Alzheimer’s specialists who weren’t involved in the study praised the trial and described the findings as “exciting.” But they also highlighted its limitations.
Alvaro Pascual-Leone, MD, PhD, professor of neurology at Harvard Medical School and chief medical officer of Linus Health, said the study represents impressive progress after 60-plus trials examining anti-amyloid monoclonal antibodies. “This is the first trial that shows a clinical benefit that can be measured,” he said.
However, it’s unclear whether the changes “are really going to make a difference in people’s lives,” he said. The drug is likely to be expensive, owing to the large investment needed for research, he added, and patients will have to undergo costly testing, such as PET scans and spinal taps.
Still, “this could be a valuable adjunct to the armamentarium we have,” which includes interventions such as lifestyle changes, he said.
Howard Fillit, MD, cofounder and chief science officer at the Alzheimer’s Drug Discovery Foundation, noted that the trial reached its primary and secondary endpoints and that the drug had what he called a “modest” effect on cognition.
However, the drugmaker will need to explore the adverse effects, he said, especially among patients with atrial fibrillation who take anticoagulants. And, he said, medicine is still far from the ultimate goal – fully reversing cognitive decline.
Michael Weiner, MD, president of the CTAD22 Scientific Committee, noted in a press release that there is “growing evidence” that some antiamyloid therapies, “especially lecanemab and donanemab” have shown promising results.
“Unfortunately, these treatments are also associated with abnormal differences seen in imaging, including brain swelling and bleeding in the brain,” said Dr. Weiner, professor of radiology, medicine, and neurology at the University of California, San Francisco.
“There is considerable controversy concerning the significance and impact of these findings, including whether or not governments and medical insurance will provide financial coverage for such treatments,” he added.